The binding of polyelectrolytes to gold nanoparticles for stabilization has been described (1). When mixing a polyelectrolyte solution with gold nanoparticles, the polymer composition, length, concentration, and total salt concentration all influence the coating of particles with polyelectrolytes (2). More specifically, high salt concentrations (0.05-0.1 M NaCl) have been found to cause aggregation of gold nanoparticles stabilized with polyelectrolytes (1, 2). This represents a significant limitation to coating nanoparticles with polyelectrolytes (2), and also severely limits the utility of polyanion coating technology since many applications such as biomolecule sensing require stability to electrolytes as well as temperature. For example, nucleic acid detection is typically performed in buffers that contain salt which promote nucleic acid hybridization, and biological fluids (e.g. urine) also contain elevated electrolyte concentrations which would destabilize polyelectrolyte nanoparticle complexes. Accordingly, a method for binding polyelectrolytes to nanoparticles that provides conjugates that are stable to electrolytes as well as temperature, conditions which are typically found in applications such as biomolecule sensing, would be highly desirable.